Routing Number Grounding Data

Overview

An ABA routing number lookup API: use it as a routing number checker or routing number validation API in ACH payment forms, payroll and payout onboarding. Send a nine-digit US routing number: input that fails the ABA mod-10 check digit is rejected with a 400 before any lookup, and a valid number returns the bank name from a routing number database that is refreshed on a weekly cycle. Each match includes the routing type (primary, thrift, electronic or government), the Federal Reserve district by name and number, whether the number is a FedACH participant and whether it can receive Fedwire Funds transfers, and, for banks that publish a routing number list by state, the states the bank assigns the number to. Paid plans add the registered street address, city and ZIP code, office and record-type codes, the successor routing number when a bank has retired one, the Fedwire telegraphic name with funds and book-entry eligibility, and the servicing Federal Reserve office and change date from the FedACH directory.

Live Test Routing Number Grounding Data Source →

The tool

Once your client is connected to the VerveContext server, this appears in its tool list as RoutingNumberGroundingData. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "RoutingNumberGroundingData",
  "arguments": {
    "routing": "121000358"
  }
}

You do not name the tool yourself; the model picks it. Asking about 121000358 in the terms this source covers is enough for it to reach for RoutingNumberGroundingData on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every source in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervecontext": {
      "url": "https://api.vervecontext.com/v1/mcp"
    }
  }
}

https://api.vervecontext.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "routing_number": "121000358",
    "office_code": "O",
    "record_type_code": "1",
    "new_routing_number": "000000000",
    "bank": "BANK OF AMERICA, N.A.",
    "address": "8001 VILLA PARK DRIVE",
    "city": "HENRICO",
    "state": "VA",
    "zip": "23228",
    "zip_extension": "0000",
    "country": "US",
    "federal_reserve_district": "San Francisco",
    "federal_reserve_district_number": 12,
    "federal_reserve_states": [
      "AK",
      "AS",
      "AZ",
      "CA",
      "GU",
      "HI",
      "ID",
      "MP",
      "NV",
      "OR",
      "UT",
      "WA"
    ],
    "address_in_district": false,
    "states_served": [
      "CA"
    ],
    "latitude": 37.621745,
    "longitude": -77.48896,
    "timezone": "America/New_York",
    "routing_type": "primary",
    "is_valid_checksum": true,
    "routing_analysis": {
      "is_head_office": true,
      "is_branch": false,
      "is_federal_reserve_bank": false,
      "is_active": true,
      "replaced_by": null
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Why ground on it

A model can produce something that looks like this answer from its training data, and be confidently out of date or simply wrong. This source returns the current value in a shape you can check, which is the difference between an answer you can cite and one you have to hedge.

Point an evaluation at routing_number: it is the field most worth pinning a claim to, and it is either present and current or absent — never plausibly invented.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 10 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Direct Deposit Setup

When onboarding new hires, payroll systems validate the entered routing number and auto-fill the financial institution name before issuing paychecks.

ACH Transfer Verification

To prevent transfer rejections, payment processors test mod-10 checksums and confirm the receiving bank matches customer paperwork before scheduling debits.

Accounting Vendor Onboarding

Procurement teams verify supplier banking details during vendor registration to catch typos and detect obsolete routing numbers before sending disbursements.

Merchant Account Enrollment

Reject mistyped routing numbers during merchant signup and show the bank name back to the applicant, so a wrong digit is caught before the first settlement instead of after a returned payment.

Other ways to use Routing Number Grounding Data

Set up Routing Number Grounding Data on VerveContext, or reach the same source a different way. Your VerveContext account and credits work on all of them — one key, one balance.

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